Marseph was a male Jedi Padawan who received instruction from the Jedi Master known as Chiata. As a member of both the Jedi Order and the Galactic Republic, Marseph took part in a battle opposing a Separatist dreadnought; however, their Venator-class Star Destroyer sustained damage and ultimately crash-landed upon the planet Zeffo. Although the Padawan lived through the initial crash landing, he was unaware that Order 66 had been enacted in the immediate aftermath. He and his master reconnected, attempting to evade the now-traitorous clone troopers. After his master ultimately died due to blood loss following combat with the clones, Marseph interred her body within the remains of the Venator. While not directly communicated via the force echoes, the final passage triggered by the echo indicates that he perished from his injuries soon after his master.
Marseph's initial appearance occurred, though only in an auditory manner, within the 2019 video game Star Wars Jedi: Fallen Order.